Auxiliary Protective Cooling System for Liquid Cooled Diesel Emissions System Components

ABSTRACT

A system for providing auxiliary cooling of liquid cooled components of a diesel emissions system. The system would include an auxiliary coolant feed(s) connected in series and/or in parallel to a primary coolant feed(s) for the liquid cooled components. It would also include a computerized controller(s) configured to operate the auxiliary coolant feed(s) in response to an uncontrolled engine shutdown.

CROSS REFERENCE TO RELATED APPLICATIONS

This disclosure claims the benefit of U.S. Provisional Application No. 61/862,081 filed on Aug. 4, 2013 which is hereby incorporated by reference.

TECHNICAL FIELD

This disclosure relates to all EPA Tier 4/EU Stage 3 compliant diesel engines using emissions systems with liquid cooled components.

BACKGROUND

The statements in this section merely provide background information related to the present disclosure. Accordingly, such statements are not intended to constitute an admission of prior art.

Modern diesel engines must now comply with strict EPA Tier 4/EU Stage 3 emissions standards to be sold in many regions of the world. To meet these standards complex emissions reduction systems must be installed downstream from engines' exhaust outlets. These systems often must operate at extreme temperatures to reduce exhaust particulate matter counts and to activate catalytic reactions required to hit mandated emissions targets.

Due to the extreme operating temperatures required, modern emissions systems typically have many liquid cooled components. The components include diesel particulate filter (DPF) cleanout burner heads, diesel emission fluid (DEF) injector nozzles, onboard electronics, and manifolds.

Many of these critical components can be severely damaged by an uncontrolled hot engine shutdown. As a result, many engines must perform a delayed engine shutdown after key-off at idle speeds with little to no load and all regenerative emissions components off. This allows the coolant and exhaust streams to bring the emissions system down to safe shutdown temperatures.

SUMMARY

A system for providing auxiliary cooling of liquid cooled components of a diesel emissions system. The system would include an auxiliary coolant feed(s) connected in series and/or in parallel to a primary coolant feed(s) for the liquid cooled components. It would also include a computerized controller(s) configured to operate the auxiliary coolant feed(s) in response to an uncontrolled engine shutdown.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 illustrates an exemplary embodiment of a layout of an EPA Tier 4/EU Stage 3 compliant diesel engine exhaust system, showing an exemplary configuration of several of the liquid cooled components in the system and how an auxiliary cooling system can be spliced into the existing cooling system, in accordance with the present disclosure.

DETAILED DESCRIPTION

EPA Tier 4/EU State 3 compliant diesel engines have liquid cooled components that can be damaged during an uncontrolled hot engine shutdown. These components can be protected from the damaging effects of uncontrolled hot engine shutdowns with an auxiliary cooling system that keeps coolant flowing even when the engine is shut off.

Under certain circumstances, a proper delayed engine shutdown is not possible. These situations include running out of fuel, engine protection system forced shutdowns, manual forced or emergency shutdowns, or engine overloading resulting in stalling. When these often unpreventable events occur, emissions system component damage can occur. Damaged emissions systems can result in machine downtime that costs owners and operators time and money.

This disclosure provides a system and method to keep coolant flowing to the liquid cooled parts of a diesel emission system even when the engine is not operating.

Splicing an auxiliary coolant feed into a diesel emissions system's existing cooling system can bring the liquid cooled parts of the system down to safe shutdown temperatures. This will mitigate the risk of the liquid cooled components being damaged after an uncontrolled hot engine shutdown.

Typically, such a system would not be able to assist with the cooling of “dry” components in the emissions system.

Referencing FIG. 1, 1 The exhaust enters the diesel emissions system. 2 A typical first stage in the emissions system may contain a diesel oxidation catalyst(s) and/or a diesel particulate filter(s). 3 The exhaust stream may then enter a mixing stage where it is infused with diesel emissions fluid. 4 The doped exhaust stream may then enter another stage where it passes through selective catalytic reduction catalyst(s) and/or an ammonia oxidation catalyst. 5 The exhaust would then exit the emissions system.

6 Some emissions system may include an on-board diesel particulate filter cleanout burner(s). These burners typically operate at extremely high temperatures and must be liquid cooled. 7 Diesel emission fluid is typically injected into the exhaust stream on the back side of a diesel particulate filter via an injector head(s). These injector heads are typically liquid cooled because they operate at extreme exhaust temperatures. They are particularly vulnerable when downstream from a diesel particulate filter cleanout burner(s). 8 Other temperature sensitive components such as controllers, sensors, and manifold may be liquid cooled on a diesel emission system.

9 The emissions system's normal coolant source(s) would be the same as that for the auxiliary cooling system. 10 The emission system's normal coolant pump(s) would be independent of the 11 auxiliary cooling system's cooling pump(s). 12 A one-way flow valve(s) may be needed on the emissions system's normal coolant line(s) to prevent backflow and pressure loss when the auxiliary cooling system is operating. 13 Likewise, a one-way flow valve(s) may be needed on the auxiliary cooling system's coolant line(s) to prevent backflow and pressure loss when the emissions system's normal cooling system is operating. 14 The emissions system's normal coolant line(s) would be spliced with the auxiliary coolant system's line(s) upstream from the liquid cooled components in the system. This would allow the liquid cooled component's coolant feed(s), discharge(s), and return(s) to coolant reservoir(s) to remain unaltered when the auxiliary cooling system is installed.

15 The auxiliary cooling system's pump(s) may be electrically driven, hydraulically driven, or driven mechanically by another outside system(s) that may or may not be dependant on whether or not the engine is running 16 The auxiliary cooling system's pump(s) may be triggered to operate by the engine's own control module(s), an external system's control module(s), or its own impendent control module(s). The control module(s) would know to activate the auxiliary cooling system by monitoring an electrical, pressure, temperature, rotational, or closed area network signal that indicates the operating condition of the engine.

Splicing an auxiliary coolant feed into a diesel emissions system's existing cooling system can bring the liquid cooled parts of the system down to safe shutdown temperatures when an uncontrolled hot engine shutdown occurs. The disclosed auxiliary emissions system cooling system will mitigate the risk of the liquid cooled components being damaged after an uncontrolled hot engine shutdown. Typically, such a system would not be able to assist with the cooling of “dry” components in the emissions system.

The disclosed system and method can be used in a wide variety of industrial and vehicular applications. An auxiliary emissions system cooling system could be used to protect liquid cooled emissions system components in on-highway, off-highway, industrial, marine, military, power generation, and just about any other diesel engine application.

According to one embodiment, the disclosed system includes an auxiliary coolant feed connected in parallel to a primary coolant feed for the liquid cooled components and a computerized controller configured to operate the auxiliary coolant feed in response to an uncontrolled got engine shutdown. In one embodiment, a temperature sensor within the emission system monitors a temperature within the emission system, and the computerized controller can deactivate the auxiliary coolant feed when the temperature drops below a threshold temperature. In one embodiment, a computerized controller runs the auxiliary pump for a time period validated to cool critical emissions system components to a threshold temperature.

The disclosure has described certain preferred embodiments and modifications of those embodiments. Further modifications and alterations may occur to others upon reading and understanding the specification. Therefore, it is intended that the disclosure not be limited to the particular embodiment(s) disclosed as the best mode contemplated for carrying out this disclosure, but that the disclosure will include all embodiments falling within the scope of the appended claims. 

1. A system for providing auxiliary cooling of liquid cooled components of a diesel emission system, the system comprising: an auxiliary coolant feed(s) connected in series and/or in parallel to a primary coolant feed(s) for the liquid cooled components; and a computerized controller(s) configured to operate the auxiliary coolant feed(s) in response to an uncontrolled engine shutdown.
 2. The system of claim 1, wherein the auxiliary coolant feed comprises an auxiliary coolant pump(s).
 3. The system of claim 2, wherein the auxiliary coolant pump(s) is electrically driven.
 4. The system of claim 2, wherein the auxiliary coolant pump(s) is hydraulically driven.
 5. The system of claim 2, wherein the auxiliary coolant pump(s) is driven mechanically by a secondary system(s) outside of the system.
 6. The system of claim 1, further comprising a one-way valve(s) configured to prevent backflow through the primary coolant feed(s).
 7. The system of claim 1, further comprising a one-way valve(s) configured to prevent backflow through the auxiliary coolant feed(s) when the primary coolant feed(s) is in operation.
 8. The system of claim 1, wherein the primary coolant feed(s) and the auxiliary coolant feed(s) both utilize a common coolant reservoir(s).
 9. The system of claim 1, further comprising a temperature sensor(s) monitoring a temperature(s) within the emission system; and wherein the computerized controller(s) is configured to deactivate the auxiliary cooling feed(s) when the temperature(s) within the emission system falls below a threshold temperature(s).
 10. The system of claim 1, further comprising a timer(s); and wherein the computerized controller(s) is configured to deactivate the auxiliary coolant feed(s) when a validated time period(s) expires know to bring component temperature(s) below a threshold temperature(s). 